JavaScript
JavaScript ConstJavaScript Const
The const keyword declares variables that never change.
Read Time
5 min readDifficulty
BeginnerLast Updated
Jun 15, 2026Version
v1.0.0Introduction
JavaScript uses `const` for values that must remain exactly the same throughout the entire program. Developers use this for configuration values, arrays, and objects. You must assign a value immediately when declaring a `const`.
Key Points
- `const` variables cannot be redeclared.
- `const` variables cannot be reassigned.
- `const` requires a starting value.
- Changing properties inside a `const` object is allowed.